MID- OR LARGE-SIZED BATTERY PACK HAVING IMPROVED COOLING EFFICIENCY

Disclosed herein is a middle or large-sized battery pack configured to have a structure in which two or more battery modules, each including a plurality of battery cells or unit modules (unit cells) which can be charged and discharged, are mounted in a space defined between a pack case and a base plate, wherein cooling members, each including a heat dissipation fin disposed in contact with outsides of corresponding ones of the unit cells and a coolant conduit connected to a lower end of the heat dissipation fin to allow a coolant to flow therealong, are mounted at interfaces between the unit cells, the base plate, located below the battery modules, is configured to form a coolant flow channel having a coolant flow direction corresponding to the coolant flow direction in the coolant conduit, the pack case is coupled to the base plate in a state in which the battery modules are mounted on the base plate, and a coolant to remove heat generated from the unit modules is introduced from one side of the coolant flow channel of the base plate, flows through the coolant conduits of the respective cooling members, and is then discharged to the other side of the coolant flow channel of the base plate.